Light responsive photo-optical keyboard



P 25, 1962 I H. E. KELCHNER 3,056,030

LIGHT RESPONSIVE PHOTO-OPTICAL KEYBOARD Filed Aug. 51, 1960 2Sheets-Sheet 1 I l 4 I Ll5 L PI5 26 30 24 2e 2? I6 23 26 2O 32 JNVENTOR.HARLEY E. KELCHNER Sept. 25, 1962 H. E. KELCHNER LIGHT RESPONSIVEPHOTO-OPTICAL KEYBOARD Filed Aug. 31, 1960 PIN LUJ

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P9 PIO PII P2 P3 P4 P5 P6 2 Sheets-Sheet 2 may INVENTOR. HARLEY E.KELCHNER AGENT for long periods of time often resulting United Statesatent 3,056,030 LIGHT RESPONSIVE PHOTO-OPTICAL KEYBOARD Harley E.Kelchner, Bridgeport, Pa., assignor to Burroughs Corporation, Detroit,Mich., a corporation of Michigan Filed Aug. 31, 1960, Ser. No. 53,231 6Claims. (Cl. 250-209) wear and therefore must frequently be repaired.

Another difliculty and annoyance in these known keyboards is the manualeffort needed to pound the keys in broken fingernails and tired and sorefingers.

Therefore, it is the primary object of the present invention to providea keyboard which overcomes these and other difficulties attendant withthe operation of such known keyboards.

Another important object of the invention is to provide akeyboard'characterized by its relatively effortless and silentoperation, and its simple, inexpensive construction. More specificallyit is an object of the invention to provide a light rdiponsive keyboardoperable by the interception of light beams to effect is intendedpurpose.

In accordancekwith the above objects and first briefly described, akeyboard in accordance with the present invention comprises a coordinateoptical system or matrix consisting of rows and columns of key positionsformed at the intersections of crossing light beams directed across thekeyboard from two adjacent sides thereof to photooptical devices on theopposite sides thereby to energize the photo-optical devices and toprovide signals corresponding to each light beam. Interception of thelight beams at their crossing points, or key positions, is effectivethrough appropriate circuitry to change the signals in a manner toproduce the desired results corresponding to the particular key positionat which the beams were intercepted.

The invention may be more clearly understood when considered inconnection with the preferred embodiment of FIG. 1;

FIG. 3 is a diagrammatic plan view of the invention including a portionof associated circuitry for effecting the desired result from thekeyboard;

FIG. 4 is a fragmentary sectional view of a modified form of theinvention in its inoperative condition; and

FIG. 5 is a view similar to FIG. 4 but showing the operative conditionof this modification.

Now with particular reference to the details of the drawings, and firstto FIG. 1, it will be understood that while the keyboard, designated bythe numeral 10, is shown incorporated in a typewriter 12, it is alsoadapted for use in other business machines such as calculating machinesor cash registers, or even as a remote control keyboard for effectingcertain functions in associated apparatus remote from the keyboard.

The invention employs the interception of light beams to activatedesired circuitry for actuating associated apparatus, which in thepresent embodiment comprises the type bars 14 of the typewriter. To thisend, and with reference to FIGS. 2 and 3, it is seen that the keyboardis formed as a panel 16 with a plurality of recesses or pockets 18disposed in rows and columns. While the recesses are shown in squareshape, it will be understood that they may be formed in other suitableshapes, as desired. The recesses are numbered or otherwise designatedgenerally in accordance with the arrangement of the keys on a-normaltypewriter. Certain liberties have been taken with the normalarrangement in order to simplify the description and without detrimentto a clear understanding of the invention, it being understood thatthese are by way of example, and that other designations may be usedaccording to the particular use of the keyboard.

Positioned across the top and the left side of the keyboard, as seen inFIG. 3, are light sources comprising a plurality of lamps L1 through L12and L13 through L16, respectively, one for each column 1-2, 2X, 3-C,etc. and each row 1-TAB, QRET, etc. Similarly a plurality ofphoto-optical devices, such as photocells P1 through P12 and P13 andP16, are positioned across the bottom and right side respectively of thekeyboard, one for each column and row and positioned to receive lightdirected from the lamps through the light paths formed by the recessesand the slots or apertures 20 through the walls of the recesses. Asshown in FIG. 2 the keyboard is secured within the housing shell 22 ofthe typewriter by suitable means, not shown. The lamps are mounted insockets 24 carried by a flange member 26 secured to the bottom surface27 of the keyboard panel 16 as by screws 28. The photocells are mountedon angle members 30 secured to the edges of panel 16 as by screws 32.

In its operation, as stated above, the invention employs the principleof interception of light beams to activate desired circuitryelectronically thus to accomplish the conveying of information to theassociated machine or other processing equipment, the typewriter in thiscase.

In the preferred form of the invention such interception is accomplishedmerely by inserting the finger tips in recesses 18 as indicated inbroken lines 34 on FIG. 2. Sometimes for physiological or other reasonsit is desired to have the operator press a key. In these cases themodified form of the invention shown in FIGS. 4 and 5 -may be employed.Instead of the operators finger tips on the key is intercepting thelight beam, a plunger 36 is provided in each of the recesses 18 for thispurpose. Each of the plungers is connected to the lower end of aconnecting rod 38 extending through an aperture 39 in shell 22, andwhich has a key 40 on its upper end. Light spring pressure normally tomaintain the key in its raised or inoperative condition, as seen in FIG.4, is provided by a light spring 42 surrounding the rod 38 between thehousing shell 22 and the key 40. Light finger tip pressure effective todepress a plunger in its recess, as seen in FIG. 5, thus to interceptthe crossing light beams at any coordinate point. Removal of thepressure will, of course, permit the spring to return the plunger to itsinoperative condition.

During operation of the apparatus the lamps S1 through S16 will beenergized from a suitable source of electrical energy, not shown. Thelight beams from the lamps will pass through the slots 20 and the matrixof recesses 18 thus causing their respective photocell B1 through P16 tobe in an ON condition. Interception of the light beams at any coordinateposition in the matrix, as by a finger tip or plunger, is elfective toactuate its associated utilization device, in this case a solenoidactuated type bar 14, in the manner now to be described. The circuitryfor only four of the forty-eight coordinate 1 passes through the lightbeams a) positions shown in FIG. 3 has been illustrated, and as theoperation of all is effected in the same manner, only one is describedin detail.

In its normal condition with the lamps L1 through L16 energized, butwithout any light beams being intercepted, the light beam from lamp L1passes through the column light path formed by slots 20 and recesses 18in the 1, A, Q and Z positions to place photocell P1 in its Oncondition. Thus the positive source of voltage as shown at the anode ofphotocell P1 would appear as a high or conducting condition at the diodeD2. Also in the normal condition, the light beam from lamp L16 the rowlight path formed by the slots and recesses in the 1, 2, 3, 4, 5, 6, 7,8, 9, 0*, Blank and Tab Key positions causes the photocell P16 to be inthe On condition. Thus, the source of positive voltage (l-) shown at theanode of P16, appears at diode D1 causing it to be in a conductingposition.

Should the light beams at the recess labeled 1 in the upper left handcorner of the keyboard be intercepted, from L1 and L16 to theirrespective photoelectric device P1 and P16 would be cut off. Under theseconditions the positive condition would no longer appear at the anode ofthe diodes D1 and D2, and the mutual conduction point between thecathodes of these diodes assumes a lower voltage condition near thenegative source of potential shown by the minus sign This negativesource is effective to operate a utilization device, which in turncauses the corresponding type bar 14 to be actuated. More specifically,an amplifier AMP, in the circuit is triggered by the drop in voltage totrigger a thyratron device T which is used to actuated a solenoid S1 tooperate the type bar in a manner well known in the typewriter art, sonot shown here.

'From the above it is now evident that the invention provides a simplyconstructed, inexpensive keyboard which is characterized by itsrelatively effortless and silent operation enabling its substantiallytireless and unirritiating operation for long periods of time.

What is claimed is:

1. A keyboard for business machines or the like comprising a coordinatematrix of crossing light beams, each beam terminating at and received bya photoelectric device energized thereby to produce an electric signalfor use in an associated circuitry whereby interception of the lightbeams at a crossing point to prevent them from striking their associatedphotoelectric devices is effective to change said signals in a manner toeffect action in said circuitry indicative of the particular crossoverat which the beams were intercepted.

2. A keyboard for business machines or the like comprising, meansestablishing a coordinate matrix of crossing light beams, andphotoelectric means for receiving each beam and energized thereby toproduce an electric signal for use in associated circuitry wherebyinterception of a pair of the light beams at a crossing point to preventthem from striking their associated photoelectric device is effective tochange said signals and affect said circuitry in a manner indicative ofthe particular crossing at which the beams were intercepted.

3. A keyboard for business machines and the like corn- CJI prising,means establishing two groups of light beams wherein the beams in eachgroup are individual and separate from each other, the beams of onegroup crossing those of the other group from a direction substantiallynormal thereto, and photoelectric means for receiving light from eachbeam to be energized thereby to produce an electric signal for use in anassociated circuit whereby interception of a pair of light beams at acrossing point to prevent them from striking the associatedphotoelectric device is effective to change said signals thus to effectsaid circuit in a manner indicative of the particular crossing at whichthe beams were intercepted.

4. A keyboard comprising a panel member having a plurality of aperturestherein arranged in rows and columns to form a coordinate matrix, thewalls of said apertures being slotted to form with said apertures lightpaths through said rows and columns, a source of light positioned at oneend of the light paths to direct a beam of light through each of saidlight paths, and photoelectric means positioned at the other ends ofsaid light paths to receive said beams of light and to produce anelectrical signal.

5. A keyboard comprising a panel member having a plurality of recessesarranged in rows and columns in a surface thereof to form a coordinatematrix, the walls of said recesses being slotted or apertured to formwith said recesses light paths through said rows and columns, a sourceof light positioned at one end of each light path to direct beams oflight through each of said recesses from two directions and crossing insaid recesses, photoelectric means positioned at the other end off saidlight paths to receive said beams of light and to ,produce an electricalsignal corresponding to each light path, and means utilizing said signalwhereby interception of said light beams at any of said recesses iseffective to change said signals to operate said utilization device in amanner indicative of the recess at which the beams were intercepted.

6. A machine keyboard comprising a panel member having a plurality ofrecesses arranged in rows and columns in a surface thereof to formjacoordinate matrix for instruction input to said machine, the walls ofsaid recesses being slotted or apertured to form with said recesseslight paths through said rows and columns, a plurality of lamps, meansmounting said lamps on said panel, one at one end of each row and columnto direct beams of light through said light paths to cross in saidrecesses, a plurality of photocells, one positioned at the other end ofeach row and column to receive said beams of light and to produce anelectrical signal corresponding to each light path, and means forutilizing said signal whereby interception of said light beams at any ofsaid recesses is effective to change said signals in a manner to effectoperation of said utilization device in accordance with the recess inwhich the beams were intercepted.

References Cited in the file of this patent UNITED STATES PATENTS

